Lateral medullary infarction can lead to central respiratory failure. However, in Wallenberg's syndrome, obstructive respiratory failure rarely develops. Here, we report a case of obstructive respiratory failure with stridor caused by unilateral lateral medullary infarction. A 74-year-old woman was admitted for acute right lateral medullary infarction. On the 12th day after the stroke, the patient developed respiratory failure necessitating endotracheal intubation. She could maintain good oxygen saturation and ventilation in intubated status without the assistance of mechanical ventilator, even during sleep. The pharyngo-laryngoscopy demonstrated the hypomobility of bilateral vocal cords. This case suggests that unilateral medullary infarction might be a cause of bilateral vocal cord palsy.